Conclusions
According to internal testing conducted by NVIDIA, which should be taken with a hearty helping of salt, the GeForce 6600 GT offers up to three times the performance of ATI's Radeon X600 XT in DOOM 3. The GT apparently also offers between 1.7 and 2.5 times the performance of the X600 XT in a wider range of games and benchmark applications that includes 3DMark03, AquaMark3, Call of Duty, Halo, and Unreal Tournament 2004. NVIDIA's GeForce 6600 presentation makes no mention of relative performance in Far Cry, though.

Because the GeForce 6600 GT has massive fill rate and healthy memory bandwidth advantages over the Radeon X600 XT, NVIDIA's performance claims are certainly plausible. We'll be able to test for ourselves soon; GeForce 6600 series cards are scheduled to ship out in mid to late September. Boards could show up in major retail outlets like Best Buy a little later than that, depending on when retailers schedule changes to their floor stock, but that shouldn't affect online vendors or smaller brick-and-mortar outlets. I'm not sure how rabid a retail market will exist for mid-range PCI Express graphics cards in the next couple of months, anyway.

And therein lies the problem. The fact that the initial cards will be PCI Express-only is perhaps the only chink in the GeForce 6600 series' otherwise gleaming armor. The only desktop PCI Express graphics platforms currently on the market are Intel's 900-series chipsets, which require space-heater Prescott Pentium 4 processors that are hardly popular among gamers and enthusiasts. Major OEMs offering Prescott- and Celeron D-based systems may be eager to offer GeForce 6600 series cards with their Intel PCI Express systems, but that doesn't do much for gamers and enthusiasts looking for a $200 graphics upgrade. We'll probably need to see a PCI Express graphics platform for the Athlon 64 or an AGP implementation of NV43 before the GeForce 6600 series stands a chance of taking off among gamers and enthusiasts.

In the end, the GeForce 6600 series is exactly the kind of trickle down I like to see in the graphics industry. The 6600s bring Shader Model 3.0, 32-bit internal precision, and 64-bit blending to lower price points and more mainstream products, hopefully encouraging developers to take advantage of these features in future games and applications. When NVIDIA launched the GeForce 6800 series graphics processors, they pledged to offer a top-to-bottom line of graphics products based on GeForce 6 technology. The GeForce 6600 series brings them two steps closer to fulfilling that promise.